I'll PM you the domain so you can take a look. I'd be interested to hear your thoughts but it's a relatively small website so not sure how much data you'll be able to gather for your investigation. I may be able to share some of our data with you.

The ranking drops definitely started on 10/18. It'd be easy to blame Penguin going by dates alone, but all the signs point more towards Panda.

I too noticed a Panda-like effect on one domain in particular which started on 18th October, bang on the launch of Penguin 3.0. In this instance it was negative movement. I gave it a few days to let the dust settle before performing a thorough analysis of the decline.

On initial glance the date of the drops (which correlate directly with the launch of Penguin) could have easily labelled Penguin as the cause but it just didn't add up. The link profile in itself is relatively clean - sure there are a handful of old school type links which may be flagged as a lesser quality than desired, but it's not the type of link profile you would immediately associate with Penguin related factors.

We noted drops on several long-tail keywords on deep internal pages which had no associated links, let alone ones of a poor quality. It crossed my mind that the drops on the long-tail keywords could have been the knock-on effect of devaluation else where, but core internal pages as well as the homepage of the website remain unaffected.

Moreover the long-tail keywords in question were synonyms or variants of other keywords which were poorly reflected within the content of each affected web page, again pointing more towards the likelihood of a Panda related shift rather than Penguin.

This is only scratching the surface. I spent quite some time digging pretty deep and I can say with 100% confidence that the impact, in this case at least, is Panda related.

Following on from Dr Pete's fantastic post HP Group have pulled together some research data charting the impact of the EMD algorithm update across 5000 keywords. I'd recommend reading the post in full but, to summarise, our findings were as follows:

-the average EMD ranking fell from #13.4 down to #26.6-the average PMD ranking fell from #39.7 down to #47.7-the average top10 EMD fell from #3.2 down to #11.9-the average top10 PMD fell from #5.2 down to #12-8% of EMDs that were initially placed in the top 10 dropped out of the top 100 completely (as did 5.7% of PMDs)

The data is well worth a read - http://www.highposition.com/blog/googles-emd-update-the-numbers/